Butterbur: Uses, Benefits, Dosage & Safety
Last updated: June 2026 · Reviewed by the FactoWiki Editorial Team for clarity and source accuracy
Quick summary
Butterbur is a herb with reasonably good evidence for migraine and allergic rhinitis — but only purified extracts free of toxic compounds are safe to use.
What is Butterbur?
Butterbur (Petasites hybridus) is a marsh plant used traditionally for pain, spasms and allergies. Purified extracts standardised to petasins and free of pyrrolizidine alkaloids are used in supplements.
What Butterbur is commonly used for
In supplements, Butterbur is most often included for respiratory & lung health, brain & memory support. It is used as nutritional support, not as a treatment for any medical condition — the distinction matters, because the claims on a sales page are often stronger than the evidence allows.
How Butterbur works
Petasins appear to reduce inflammation and relax smooth muscle and blood vessels, which underlies butterbur's investigated uses in migraine and allergic nasal symptoms.
What the evidence says
Here's an honest snapshot of what published research suggests about Butterbur — including where the evidence is limited.
- Butterbur has some of the better botanical evidence for reducing migraine frequency and for easing hay-fever symptoms in randomised trials, which is why a neurology guideline once supported it before liver-safety concerns tempered recommendations.
- Study quality and doses vary, and a result seen in research doesn't guarantee the same for any individual — use the sources below to check the current evidence on Butterbur rather than relying on marketing claims.
Typical dosage used in studies
Migraine trials used about 50–75 mg twice daily of a standardised PA-free extract. Only certified pyrrolizidine-alkaloid-free products should ever be used. This is general information from research, not a personal recommendation or a dosing instruction.
Side effects and safety
Raw butterbur contains pyrrolizidine alkaloids that are toxic to the liver and potentially carcinogenic — only PA-free extracts are acceptable. Even then, liver-injury reports exist, so medical supervision and avoidance in pregnancy are advised. As with any supplement, it's sensible to introduce Butterbur on its own, use a trusted brand, and stop if you notice any reaction.
Medication interactions and who should avoid Butterbur
Medication & safety check
Herbs interact with prescription medicines more often than people expect — affecting drug levels, bleeding, blood pressure, blood sugar or sedation — and Butterbur is no exception. If you take any regular medication, are pregnant or breastfeeding, or manage a health condition, confirm Butterbur is appropriate for you before starting.
This is general information, not personal medical advice. If you take any medication, are pregnant or breastfeeding, or have a health condition, confirm it's safe to use Butterbur with your doctor or pharmacist first.
Sources & further reading
For authoritative background and the current research base on Butterbur, consult:
- PubMed — search the research on Butterbur
- NCCIH — Herbs at a Glance
- MedlinePlus — herbs & supplements
- MedlinePlus — drugs, herbs & supplements
Frequently asked questions
Does Butterbur actually work?
Butterbur has some of the better botanical evidence for reducing migraine frequency and for easing hay-fever symptoms in randomised trials, which is why a neurology guideline once supported it before liver-safety concerns tempered recommendations. As with most supplements, results vary between people and the marketing is often stronger than the evidence — so it's worth checking the research before relying on it.
Is Butterbur safe to take?
For most healthy adults at normal doses it's generally well tolerated, but there are real cautions. Raw butterbur contains pyrrolizidine alkaloids that are toxic to the liver and potentially carcinogenic — only PA-free extracts are acceptable. Even then, liver-injury reports exist, so medical supervision and avoidance in pregnancy are advised. If you take medication, are pregnant or breastfeeding, or have a health condition, check with a doctor or pharmacist first.
What is Butterbur used for?
In supplements, Butterbur is mainly included for respiratory & lung health, brain & memory support — as nutritional support, not as a treatment for any medical condition.
Where you'll find Butterbur
On FactoWiki, Butterbur is the kind of ingredient you'll see discussed in these supplement categories. Each category guide breaks down what the evidence does and doesn't support.
Related ingredients to explore
Ingredients often studied or formulated alongside Butterbur — useful for understanding the full picture of a formula.